Effect of vitamin A supplementation on immune function of well-nourished children suffering from vitamin A deficiency in China

OBJECTIVE

To clearly clarify the protective effect of vitamin A supplementation on immune function of well-nourished children suffering from vitamin A deficiency.

METHODS

Three hundred sixty-two children in two kindergartens in Wuhan China were enrolled. Detailed dietary assessment and anthropometry were undertaken to facilitate the exclusion of malnourished children. Seventy vitamin A-deficient children with informed consent were randomly divided into the vitamin A-deficient-supplemented group and vitamin A-deficient placebo group, 35 vitamin A-sufficient children (age- and sex-matched with the vitamin A-deficient-supplemented group children) were selected as vitamin A-sufficient placebo group. The baseline and follow-up level of selected immune parameters of the 105 children in three intervention groups were compared.

RESULTS

The total proportion of severe and marginal vitamin A-deficient children was 10.9 and 21.96%, respectively. At baseline, the serum complement C3 and sIgA level of vitamin A-sufficient children was significantly higher than that of vitamin A-deficient children (P < 0.05). However, the serum lysozyme level of vitamin A-sufficient children was inversely lower. After intervention, vitamin A-deficient-supplemented children increased serum vitamin A, complement C3 and sIgA level, but their serum lysozyme level inversely decreased.

CONCLUSIONS

Vitamin A deficiency was still a serious health problem in children in China cities. Vitamin A supplementation was efficacious in ameliorating serum vitamin A status and partially impaired immune function of well-nourished children suffering from vitamin A deficiency.

Transcriptional regulation of Trk family neurotrophin receptors

The Trk family of neurotrophin receptors plays essential roles in cell fate specification, survival, growth, and differentiation. Their expression patterns are complex and dynamically regulated under many physiological and pathological conditions. However, the molecular mechanisms that control their tissue-specific expression are largely unknown. In this report, we review current knowledge about the transcriptional regulation of Trk receptors.

Atrial natriuretic peptide inhibits the actions of FSH and forskolin in meiotic maturation of pig oocytes via different signalling pathways

Atrial natriuretic peptide (ANP) as well as its receptors is found in mammalian ovary and follicular cells and its function in oocyte meiotic maturation has also been reported in Xenopus, hamster and rat. But the results are controversial and the physiological mechanism of ANP on oocyte maturation is not clear, especially the relationship between gonadotrophin and ANP as well as the signal transduction, and these need further study. The present study conducted experiments to examine these questions by using drug treatment and Western blot analysis and focused on pig oocyte meiotic maturation and cumulus expansion in vitro. The results revealed that ANP could inhibited FSH-induced pig oocyte maturation and cumulus expansion and prevent the full phosphorylation of mitogen-activated protein kinase in both oocytes and cumulus cells, and that these inhibitory effects could be mimicked by 8-Br-cyclic guanosine 5'-monophosphate (8-Br-cGMP), but blocked by a protein kinase G (PKG) inhibitor KT5823. Zaprinast, a cGMP-specific phosphodiesterase inhibitor, could enhance the inhibitory effect of ANP on oocyte maturation. A specific analogue of ANP, C-ANP-(4-23), which binds to the natriuretic peptide receptor-C (NPRC), had no effect in either FSH-induced or spontaneous oocyte maturation. Treatment with forskolin, a stimulator of adenylate cyclase, had a biphasic effect; 44 h treatment induced cumulus expansion but inhibited oocyte maturation while 2 h treatment induced maturation of cumulus-enclosed oocytes (CEOs). Both ANP and C-ANP-(4-23) could inhibit the effect of forskolin on CEO maturation, and these inhibitory effects of ANP/C-ANP-(4-23) could be blocked by preincubation with pertussis toxin (PT), consistent with mediation by a Gi protein(s) in the cumulus cells. All these results suggest that ANP is a multifunctional regulator of FSH and forskolin on pig CEO maturation by two signalling mechanisms: one is via a cGMP/PKG pathway, the other is via NPRC receptors in cumulus cells and the activation of the PT-sensitive Gi protein(s).

Biodegradation of sediment-bound PAHs in field-contaminated sediment

The biodegradation of polycyclic aromatic hydrocarbons (PAHs) has been reported to occur under aerobic, sulfate reducing, and denitrifying conditions. PAHs present in contaminated sites, however, are known for their persistence. Most published studies were conducted in systems where PAHs were freshly spiked, and biodegradation was often tested using pure cultures or enrichments. This paper investigated the degradation potentials of PAHs that were present in aged contaminated sediment by indigenous bacteria, where the limited bioavailability of PAHs due to aging played an important role. The sediment and the overlaying water were collected from a contaminated site to prepare sediment-water slurries, and the sediment served as both the media containing PAH substrates and the habitat for the indigenous microorganisms. Reduced sulfur compounds present in the sediment caused rapid oxygen depletion due to extensive activities of sulfur-oxidizing bacteria and could result in a dramatic pH drop. Once oxygen depletion and acidification problems were avoided, substantial removals of two-, three-, four-, and five-ring PAHs were achieved aerobically, though the extent of degradations was smaller than what was reported for freshly spiked PAHs. The amendment of inorganic N and P, co-substrates, or surfactant Triton X-100 did not enhance the level of degradations appreciably. Under denitrifying conditions, no distinct PAH degradation was observed, while the complete denitrification of nitrate to nitrogen occurred stoichiometrically with a concomitant increase in sulfate concentration, indicating the dominance of autotrophic denitrifiers. The addition of ethanol or acetic acid did not stimulate PAH degradation. Substantial PAH degradation attributed to sulfate reduction was only observed for phenanthrene, the low-ring PAH existing in a highest initial concentration. Addition of ethanol or acetic acid did not change this finding. This is the first study to our knowledge that revealed the importance of indigenous bacteria involved in natural sulfur cycling in determining degradation behavior of PAHs.

Stress in expatriates

With economic globalization, the rate and effects of culture shock stress in expatriates and their families are expected to increase. The stressor may occur from the micro-environment, the macro-environment, or the mega-environment. The effects of stress are frequently due to predictable reactions such as insecurity, distress, and homesickness. These symptoms can progress to more severe psychosomatic symptoms, including depressive reactions and overt psychopathic behavior. Cross-cultural training programs are currently the best preventive strategy for culture shock and subsequent stress; however, the true efficacy of these programs is not well characterized. Substance abuse is probably a significant underlying problem for international business travelers; however, the true magnitude and effects of this issue are not well characterized in the expatriate community. There are substantial opportunities for additional medical research in these areas.

Developmental biology meets with reproductive engineering; interdisciplinary science area as a breakthrough

It has been postulated many times that different scientific topics and strategies often encounter each other, which create cutting edge research field resulting in further significant progresses of science. This was also a lesson bestowed by Prof. Raymond Wegmann where he created innovative research field for biology, molecular biology and biochemistry-biophysics. Progresses of developmental biology were boosted by molecular biology and reproductive engineering where ES cells and embryonic manipulation are necessary. There are no questions about the utility of their technologies. Reviews on their contributions with respect to the condition of genome manipulation are addressed.

Simulation program for wastewater coagulation

The lack of comprehensive simulation models for wastewater coagulation is one of the obstacles to achieving optimal coagulant dosing. Two approaches for developing a model to describe the coagulation process are presented. The comprehensiveness in describing the influent quality with several parameters, rather than with one parameter, is identified to give high efficiency in dosing models based on algorithms constructed using the partial least squares method. The concept was tested on two full-scale wastewater treatment plants, with coagulant savings and effluent quality improvements. Significant differences were observed with the increase of online parameters in the models. The second approach is based on distribution of coagulant for particle and phosphate removal processes and is discussed for inert fractions. The concept is integrated into existing simulation software as a module. The calibration results and dosage predictions are demonstrated.

Molecular cloning, genetic mapping, and expression analysis of four zebrafish c/ebp genes

The CCAAT/enhancer binding protein family (C/EBP) are transcription factors that play integral roles in the development and function of many organ systems, including hematopoietic cells, adipose tissues, and liver. We have identified and characterized putative zebrafish orthologs of mammalian C/EBP alpha, beta, gamma, and delta using low-stringency hybridization screening and computer searches of the GenBank EST database. c/ebpa and g were mapped within 1 cM of each other on linkage group (LG) 7, syntenic with human CEBPA and G genes on chromosome 19. c/ebpb was mapped to LG8, and c/ebpd was mapped to LG24, on the same LG as a recently identified unique c/ebp in zebrafish, c/ebp1. The mapping of these genes established new syntenic relationships between LG8 and human chromosome 20, extended existing synteny between LG7 and human chromosome 19, and confirmed the synteny between LG24 and human chromosome 8. In addition, these syntenies between zebrafish and human chromosomes are also conserved in the mouse genome. To characterize the expression of these genes, RNA in situ hybridization in embryos of wild type and a hematopoietic mutant, cloche, was performed. The results showed that zebrafish c/ebpa, b, g, and d were expressed in many embryonic tissues. c/ebpa and b were expressed in a subset of hematopoietic cells in a region consistent with myeloid expression. In addition, there was expression of c/ebpa and b in the liver and c/ebpa, b, and d in regions of the gastrointestinal tract. The expression of the c/ebps may serve as important markers for analysis of myelopoiesis, hepatic development, and other developmental processes in the future.

Intercalation and controlled release of pharmaceutically active compounds from a layered double hydroxide

A series of pharmaceutically active compounds including diclofenac, gemfibrozil, ibuprofen, naproxen, 2-propylpentanoic acid, 4-biphenylacetic acid and tolfenamic acid can be reversibly intercalated into a layered double hydroxide, initial studies suggest that these materials may have application as the basis of a novel tuneable drug delivery system.

A single nucleotide polymorphism in the matrix metalloproteinase-1 promoter enhances lung cancer susceptibility

Extracellular matrix-degrading matrix metalloproteinase-1 (MMP-1) is one of the interstitial collagenases likely to be involved in tumor invasion and metastasis. MMP-1 may also contribute to tumor initiation and development by altering the cellular microenvironment that facilitates tumor formation. Recent studies have found that overexpression of MMP-1 is associated with the initial stages of cancer development in addition to promoting cellular invasion; however, preexisting oncogenic mutations or chemical carcinogens are required to initiate tumorigenesis as well. There is a single nucleotide polymorphism located in the promoter region of MMP-1 that partially regulates gene expression. The 2G/2G genotype enhances transcriptional activity and may be associated with an increased lung cancer risk. Using a case-control study, we tested the hypotheses that (a) individuals with the 2G/2G genotype may be at an increased risk for lung cancer; and (b) the risk should be greatly elevated in smoking individuals. PCR-RFLP was used to determine the MMP-1 genotypes in 456 lung-cancer cases and 451 frequency-matched controls of Caucasian ethnicity. Overall, there was a significant association between the 2G/2G genotype and lung cancer risk [odds ratio (OR), 1.76; 95% confidence interval (CI), 1.29-2.39]. In current smokers, the lung cancer risk associated with the 2G/2G genotype was significantly elevated (OR, 3.16; 95% CI, 1.87-5.35). However, this association was less evident in former smokers (OR, 1.23; 95% CI, 0.81-1.87) and absent in never smokers (OR, 1.09; 95% CI, 0.31-3.91). Similarly, this risk was more evident in heavy smokers (OR, 2.55; 95% CI, 1.61-4.03) than in light smokers (OR, 1.40; 95% CI, 0.84-2.32). Interestingly, men were observed to have a 2.15-fold increased lung cancer risk (OR, 2.15; 95% CI, 1.42-3.26) compared with women (OR, 1.34; 95% CI, 0.84-2.15). Furthermore, subjects with 2G/2G genotype developed lung cancer earlier (60.94 +/- 0.64 years old) than patients with 1G/1G and 1G/2G genotypes (62.91 +/- 0.59 years old; P = 0.024). Our data demonstrate that the 2G/2G genotype enhances lung cancer susceptibility especially in current smokers. To our knowledge, these results report the first molecular epidemiological evidence of the MMP-1 promoter polymorphism associated with the development of lung cancer in the presence of continuing carcinogenic exposure.

Histochemical study of transmyocardial laser channels in dogs

OBJECTIVE

Laser-induced myocardial injury was investigated in a canine transmyocardial laser revascularization model.

METHODS

A total of 23 channels were created in the left ventricles of 5 animals with a CO2 laser. Four animals were sacrificed immediately and one at week 2. Lactate dehydrogenase and succinate dehydrogenase in channel regions were examined with a Nitro-BT method staining.

RESULTS

Immediately after the procedure, laser channels and surrounding injured myocardium could be stratified from the center to the border into 5 concentric zones, i.e., vaporized zone, carbonized zone, enzyme-disappeared zone, enzyme-decreased zone and enzyme-concentrated zone. Two weeks later, the phenomenon disappeared.

CONCLUSIONS

Immediately after transmyocardial revascularization, there is a ring of enzyme-concentrated zone at the outermost region of injured myocardium. Two weeks later, enzyme activities of reversibly injured myocytes appear to have recovered.

Construction and application of phenytoin anion-selective electrode based on bulk acoustic wave (BAW) sensing technique

This paper describes the construction of an anion-selective bulk acoustic wave (BAW) sensor for the direct determination of phenytoin sodium for the first time. Based on the sensitive mass response of a piezoelectric quartz crystal (PQC) and selective adsorption-desorption across the modified film, the BAW sensor was fabricated by coating a polyvinylchloride (PVC) film containing activator on one side of a PQC. The method was found to be sensitive, rapid and easy to handle without pretreatment of the sample. The logarithm of the frequency shift of the PQC shows a linear relationship to the logarithm of the concentration of phenytoin over the range 6.7 x 10(-8)-8.0 x 10(-4) M with a detection limit of 1.0 x 10(-8) M at pH 10.0. Recoveries were in the range 98.5-102.0%. Influencing factors were examined and optimized. Also discussed is the preliminary application of the phenytoin BAW sensor in serum and injection. The results for real samples obtained by the proposed method agreed with those obtained by conventional methods.

[Distribution of beta-actin within hair cells in the chick: comparatived with those in the guinea pig cochleae]

OBJECTIVE

To study the distribution of beta-actin in the chicken and guinea pig cochlea hair cells.

METHOD

beta-actin immunoreactivity was observed by immunohistochemistry.

RESULT

beta-actin was located in stereocilia of hair cells and cytoplasm of marginal epithelium cells which tectorial membrane attached in basilar papilla; In the corti's organ beta-actin was present in three row outer hair cells cytoplasm and the phalangeal process and cytoplasm of the tunnel cells.

CONCLUSION

There is a common cytoskeletal protein beta-actin in the chick and guinea pig cochleae, but the distribution of beta-actin in two species are different significantly.

Induction of interleukin-8 in human neutrophils after MHC class II cross-linking with superantigens

Neutrophils have been shown to express major histocompatibility complex class II (MHC II) after stimulation. However, reports concerning the functional effect of MCH II expression are still lacking. In our hands, granulocyte-monocyte colony-stimulating factor (GM-CSF) alone and in combination with interferon (IFN)-gamma, but not IFN-gamma or interleukin (IL)-3, induced a significant level of expression of human leukocyte antigen DR on neutrophils. The addition of staphylococcal enterotoxin E to neutrophils resulted in a significant increase in IL-8 production only after prestimulation with GM-CSF alone or in combination with IFN-gamma but had no effect on neutrophils preincubated with IFN-gamma alone or IL-3. Staphylococcal enterotoxin A, another bivalent superantigen, also stimulated production of IL-8 by preincubated polymorphonuclear neutrophils, whereas staphylococcal enterotoxin A mutants that are not able to cross-link MHC II molecules failed to induce IL-8 production. Taken together, our results clearly demonstrate that after induction of MHC II, neutrophils are able to respond to MHC II-specific stimulation. These findings support the ideas that the induced MHC II complex is completely functional and that neutrophils may be able to present antigens.

On the degradability of printing and dyeing wastewater by wet air oxidation

A modified first-order kinetics model was used to study the wet air oxidation of printing and dyeing wastewater. The model simulations are in good agreement with experimental data. The results indicate that a certain fraction of organic pollutants in the printing and dyeing wastewater could not be removed even at elevated temperature and prolonged reaction time. The ratio of degradable organic matter is found independent of temperature and can be improved by using a catalyst.

[Metabolic regulation of phenylethanoid glycosides from Herba cistanches in dogs' gastrointestine]

AIM

To study the metabolic process of phenylethanoid glycosides (PhGs) in the gastrointestine of beagle dogs that were administered intragastrially process, and develop some new methods of biopharmacology on the effective position of traditional Chinese medicine.

METHODS

High-performance liquid chromatography was used to purify constituents from faeces and analyze relative contents of the three main compounds in the gastrointestinal tract at different times and in the faeces of dogs. Every sample was collected, extracted with methanol and analyzed with integration.

RESULTS

Four compounds, based on reference substances, were identified as echinacoside, acteoside, isoacteoside, and 2'-acetylacteoside from extraction of faces of dogs. Quantitative "with HPLC" analysis reveals that variation of ratios of the three main compounds is not distinct when moving in the gastrointestinal tract 7 h, that is quite different from those in faeces, in which the content of echinacoside fell from 48.0% to 16.0%, and acteoside increased from 11.0% to 34.7%.

CONCLUSION

PhGs are mainly metabolized in large intestine. Among them, a portion of echinacoside is transformed into aceteoside.

[Beta-actin changes during hair cell regeneration in the chick basilar papilla]

OBJECTIVE

To investigate the changes of beta-actin and beta-actin mRNA expression during hair cell regeneration in the chick basilar papilla(BP) following gentamicin ototoxicity.

METHODS

Thirty-six chicks were given muscular injection of gentamicin at dosage of 100 mg/kg.d for 10 consecutive days, and twelve additional chicks received injection of normal saline instead of gentamicin as controls. At 1, 3, 7, 14, 21 and 28 days after the treatment, six chicks in experimental group and two chicks in control group were sacrificed. Basilar papillas were prepared for immunohistochemistry and in situ hybridization study. beta-actin and beta-actin mRNA expression in the damaged region were histologically analyzed by computer image system.

RESULTS

beta-actin immunoreactivity of BP changed significantly after treatment with gentamicin. From the first day to the fourteenth day after gentamincin, beta-actin immunoreactivity turned positive gradually. It approximated the normal response level at the fourteenth day after treatment of gentamincin. Then increasing rate of beta-actin immunoreactivity positive response level slowed from the fourteenth day after the treatment. At seventh day after treatment, beta-actin mRNA expression in BP increased to peak value, which preceded the peak expression of beta-actin in the regenerated hair cells.

CONCLUSION

Nascent hair cells seem to mature 14 days after hair cell damage, which may play a role in auditory functional recovery.

[Separation of echinacoside by reversed-phase preparative high performance liquid chromatography]

Echinacoside, one kind of phenylethanoid glycosides (PhGs), was isolated from the stems of Cistanche tubulosa (Schenk) R. Wight with a series of steps, including solvent extraction, D101 polymer adsorption column separation, Sephadex LH-20 separation, C18 column reversed-phase preparative high performance liquid chromatographic (RP-prep-HPLC) preparation and polyamide thin-layer chromatographic detection. The purity of the product was over 98%. The chemical structure of echinacoside was identified by 1H NMR and 13C NMR. To find out the optimum condition of mobile phase of RP-prep-HPLC, several systems were used in this work. Finally acetonitrile-1% HCOOH water (18:82, V/V) system was found to be the best. On the other hand D101 polymer adsorption column and Sephadex LH-20 were also effective for PhGs separation.

mKlf7, a potential transcriptional regulator of TrkA nerve growth factor receptor expression in sensory and sympathetic neurons

Development of the nervous system relies on stringent regulation of genes that are crucial to this process. TrkA, the receptor for nerve growth factor (NGF), is tightly regulated during embryonic development and is essential for the survival and differentiation of neural crest-derived sensory and sympathetic neurons. We have previously identified a mouse TrkA enhancer and have characterized several cis regulatory elements that are important for appropriate TrkA expression in vivo. We now report the cloning of a novel gene encoding a Kruppel-like factor from a mouse dorsal root ganglion expression library. This Kruppel-like factor, named mKlf7, binds specifically to an Ikaros core binding element that is crucial for in vivo TrkA enhancer function. Using in situ hybridization, we demonstrate that mKlf7 is coexpressed with TrkA in sensory and sympathetic neurons during embryogenesis and in adulthood. These data are consistent with the idea that mKlf7 may directly regulate TrkA gene expression in the peripheral nervous system.

[Effect of p14ARF gene on cell growth of human laryngeal tumor cells and expression of endogenous p53 protein]

OBJECTIVE

To explore the inhibitory effect of p14ARF on the cell growth of laryngeal carcinoma and the expression on endogenous p53.

METHODS

p14ARF cDNA was transferred to the cell line Hep-2 of squamous cell carcinoma of the larynx by gene transfer to study the cell cycles and the expression of endogenous wild type p53 using flow cytometry, polymerase chain reaction(PCR) and Western-Blotting.

RESULTS

Expression of p14ARF significantly affected the Hep-2 cell growth. The clone-forming efficiency of the Hep-2 cells transferred with p14ARF was 57%, compared with empty vector pcDNA3. The number of 48 hours after transfer with p14ARF cDNA at both G0/G1 and G2/M was two fold as the control. The expression of endogenous wild type p53 was significantly enhanced.

CONCLUSION

Expression of p14ARF can up-regulate the expression of endogenous wild type p53 and inhibit the Hep-2 cell growth of human laryngeal squamous cell carcinoma at both G0/G1 and G2/M.